1. Field of the Invention
The present invention pertains to a friction disk for a wet-running clutch for a motor vehicle of that type having a lining carrier ring provided with connecting areas for connecting the friction disk to a drive side or to a takeoff side of a clutch, and a friction lining on at least one side of the lining carrier ring.
2. Description of the Related Art
A wet-running friction clutch for a motor vehicle is known from U.S. Pat. No. 6,910,561, in which several friction disks or plates are connected to the input side and several other disks or plates are connected to the output side of the friction clutch, where these friction disks are pressed together so that torque can be transmitted between the drive side and the takeoff side. Various measures are implemented on at least some of these friction disks to ensure that the fluid present in a wet-running clutch of this type, usually oil, will circulate in the area of the friction surfaces which interact frictionally with each other. For this purpose, fluid transport surfaces are provided on some or all of the friction disks. These surfaces act like the vanes of a turbine to circulate the fluid. These fluid transport surfaces can be formed on the friction lining carrier, but they can also be designed as circumferentially oriented surfaces of the friction linings themselves. As result, flow channels for the fluid to be circulated are formed, these channels extending, for example, from the radially inner area to the radially outer area over the entire surface of the friction disk. A highly uniform pattern of alternating flow channels and frictionally active surface areas is created. As a result of this uniform pattern, however, there arises the danger that, when the system is in rotation, the periodicity of this pattern will cause vibrations to be excited, which have a disadvantageous effect on the behavior of the clutch and which can even be perceptible in the drive train. There is also the problem that, even though these fluid flow channels can carry heat away from the areas of the friction linings immediately adjacent to the channels, they cannot carry heat away from the areas which are farther away from the fluid flow channels, i.e., from the areas over which the fluid does not flow directly. The essentially radially oriented edges which form the boundaries of the flow channels in the circumferential direction, furthermore, form flow barriers for the fluid to be circulated, especially when a clutch of this type is disengaged or partially disengaged. This can lead in turn to slippage torque and thus to an undesirable force-coupling interaction between immediately adjacent friction disks.
A friction disk for a wet-running clutch is known from U.S. Pat. No. 6,454,072, in which grooves which extend from the radially inner area to the radially outer area are provided in each of the friction lining rings to allow the fluid to flow through.